曲面上的新型光场调控研究

变换光学可以自由调控空间中的光场，超表面可以自由调控表面的相位，进而调控光场。人们利用这两个手段，设计出一系列的具有新奇功能的器件。通常情况下，超表面均是基于平面结构，而一般的应用场景都是曲面，因此发展弯曲超表面具有重要意义。由于变换光学能够自然联系到弯曲空间，通过反向定制光的路径和场的分布，把变换光学和超表面这两个方向互相融合，可以精确获得所需的结构，大大简化器件的设计，并将产生许多重要的概念。在本项目中，我们将首先发展反向变换光学，通过弯曲空间取代折射率或材料参数分布，进行光场的调控；然后我们研究弯曲表面的片上集成光子器件的设计和制备；最后我们将利用弯曲超表面，结合变换光学，设计隐身和光学幻像器件。这个项目的开展，将为新型光场调控和信息传输奠定重要的研究基础。

Transformation optics can be used to control light field in space at will, while metasurfaces can be used to control elapsed phases, and thereby manipulating the wavefront arbitrarily as well. Both have been applied to design various devices with novel functionalities. Conventionally, metasurfaces and transformation optical devices are fabricated on flat surfaces or two dimensions. We recognize the incorporation of curved surfaces can greatly relax the requirement of extreme refractive indexes in transformation optical devices and can combine metasurfaces to more generic scenarios. In this project, we will develop inverse approaches for transformation optics with curved space from prescribed trajectories and for designing metasurfaces from a set of specified electromagnetic fields. We will firstly develop the inverse transformation optics, that is to control the light field by curved space instead of profiles of refractive indexes or material parameters. Secondly, we will investigate the design and the fabrication of integrated photonic devices based on curved surfaces. Finally, we will design optical illusion devices by combining curved metasurfaces and transformation optics. The proposed project allows us to simplify device applications and also stimulates new concepts in wavefront manipulation and information processing based on geometric curvature.